*2.1. Study Area*

Lin'an District (Figure 1) in Hangzhou city is located in northwestern Zhejiang Province, bordering the main city of Hangzhou in the east and Huangshan in the west. In July 2017, Lin'an was established as a district, making it the youngest district in Hangzhou, with five streets and 13 towns (towns and streets are the smallest units in China's administrative divisions). The eastern part of Lin'an has been basically integrated into the main city of Hangzhou and is a highly urbanized area. In contrast, the western part is low hilly area with a good ecological environment and rich species diversity. It is approximately 100 km wide from east to the west and 50 km long from north to south. The hilly area accounts for 86% of this district, which is referred to as having 'nine mountains, half water and half farmland'. The elevation is high in the northwest and low in the southeast. The mountains in the northwestern part of the district are rugged, and the eastern part of the district is characterized by a staggered distribution of hilly and wide valley basins. Lin'an District is located on the southern edge of the subtropical monsoon climate zone and experiences a monsoon climate. Streams and ditches in the district show a crisscrossed pattern. The Changhua Stream, Tianmu Stream and Tiao River are part of the Qiantang River and Yangtze River systems. The agricultural industry in Lin'an District is dominated by *Carya cathayensis* (Chinese hickory) and *Phyllostachys praecox* (a cultivated species of bamboo). In 2018, the total household registered population of the whole region was 537,600, the GDP reached 53.963 billion yuan, the output value of the first, second and third largest industries accounted for 8.0%, 44.2% and 47.8%, respectively, and industry was developing well.

**Figure 1.** Geographic location of Lin'an District.
